Domed imaging systems are known and used for both entertainment and training. These systems utilize a plurality of projectors, which can be front projection or rear projection projectors. Large domes that can be used for training, such as military training, are particularly difficult to assemble and create a realistic 360° image, without seams in the screen being visible and without image problems.
Inflated domes (positive pressure) and domes inside of evacuated chambers (negative pressure) have been suggested but there is no physical support structure for the screen. U.S. Pat. No. 5,179,440 describes a “dome” made of trapezoidal-shaped screen panels or facets. Stiffeners are used to hold pieces of the screen material together. The stiffeners are straight pieces of a clear material, such as acrylic, which are attached to a superstructure using springs, providing a less than rigid structure. Light passes through the tips of the stiffeners but they do not guide the light in any manner.